--- a/modules/libpref/src/init/all.js+++ b/modules/libpref/src/init/all.js@@ -1634,17 +1634,21 @@ pref("layout.css.dpi", -1); // Set the number of device pixels per CSS pixel. A value <= 0 means choose // automatically based on user settings for the platform (e.g., "UI scale factor" // on Mac). A positive value is used as-is. This effectively controls the size // of a CSS "px". This is only used for windows on the screen, not for printing. pref("layout.css.devPixelsPerPx", "-1.0"); // Is support for the the @supports rule enabled?+#ifdef RELEASE_BUILD+pref("layout.css.supports-rule.enabled", false);+#else pref("layout.css.supports-rule.enabled", true);+#endif // Is support for CSS Flexbox enabled? pref("layout.css.flexbox.enabled", true); // Are sets of prefixed properties supported? pref("layout.css.prefixes.border-image", true); pref("layout.css.prefixes.transforms", true); pref("layout.css.prefixes.transitions", true);